Which is out of round, the wheel or the tire? For low speeds, out of round wheels or tires will generally work. But anything above 60kph (a speed I drive in even during a regular commute) is potentially dangerous. Not only due to the potential of a blow out but also because of the altered handling characteristics of the vehicle and potential longer stopping distances due to the out of round wheel/tire.

Out of round tires cannot be corrected. Out of round wheels can be machine pressed to a certain degree.